Saturday, September 24, 2011

Roger A. Pielke -- has had -- enough -- of lukewarmers

We believe Dr. Pielke framed the prudent path forward with regards to addressing the risks posed by climate change very well (emphasis added):

"The emission of CO2 into the atmosphere, and its continued accumulation in the atmosphere is changing the climate. We do not need to agree on the magnitude of its global average radiative forcing to see a need to limit this accumulation.
The biogeochemical effect of added CO2 by itself is a concern as we do
not know its consequences. At the very least, ecosystem function will
change resulting in biodiversity changes as different species react
differently to higher CO2. The prudent path, therefore, is to limit how much we change our atmosphere."

"I am very much in favor of energy
sources which minimize the input [of] gases and aerosols into the
atmosphere. Much of my career has been involved with reducing air
pollution (both in research and in policy). What we should move towards
is an economy with as small a footprint on the natural environment as
possible."

Dr. Piekle, without mentioning lukewarmers by name, gets to the heart of why their position -- climate sensitivity may be lower than estimated (which Piekle believes to be true) -- therefore we should not act to reduce emissions -- makes no logical sense. We've been there before:

Most estimates of climate sensitivity, regardless of how they are
derived (and there are several lines of evidence including comparisons
with paleoclimate, response to modern forcings like the Mount Pinatubo
eruption, and climate modeling) include in their 95% confidence interval
sensitivities between 1-2C. In some cases, the central estimate is
between 1.2-1.5C for a doubling of CO2. So favoring a low number for
climate sensitivity is not, by itself, enough to put you at odds with
the "consensus." You need the other piece – the it's-not-a-big-deal
piece. And that's where the trouble starts. . . .

Scientists estimate a warming of 2C as the upper limit of what our
civilization can adapt to, and not suffer disaster on a planetary scale.
This is probably an optimistic number . . .

The hard lower limit of climate
sensitivity -- the lowest it can possibly be and account for our direct
observations – is about 1.1C (the real number is very likely to be in
that range of 2.6C-4.1C – but we are following the "lukewarmist"
argument to see where it leads). The change in forcings expected from a
"business as usual" 21st century are +8.5W/m^2 – about 2 1/3 doublings
of CO2.

Hence with the lowball number – the number Steven Fuller
attributes not to lukewarmers but to out-and-out deniers – put us on
course for 2.5C of warming this century. In other words, the
lukewarmers' own numbers belie their causal attitude to reducing
greenhouse emissions.

Perhaps I could insert a joke here about how maybe Pielke reads the blog, but this misses the point. This isn't my idea: it's just the iron grip of logic and common sense. Could climate sensitivity be lower than we think? Sure. Would that mean it was safe to radically alter the Earth's climate? No. In fact -- and Pielke echoes this part of my argument, as well -- the very fact that we can't predict the consequences with certainty implies the need for greater caution and "as small a footprint on the natural environment as possible."

"[A]s small a footprint on the natural environment as possible." What warmist-alarmist leftist-secular-socialist ecomarxist rent-seeking climate scientist could say it better?

"Hmmm, you might be right. Perhaps climate sensitivity/crop yields/ice loss/etc will not be as bad as some think. We'll no so much more in a couple of decades. But, not to be rude, so what? Would that change anything?"

Lukewarmers like to imply that these issues are really, really important in policy terms, but don't want to have to come out and say "global warming is safe" because of how ridiculous that proposition sounds when you make the argument explicit.